What is Angular.noop used for?

Solution 1:

angular.noop is an empty function that can be used as a placeholder when you need to pass some function as a param.

function foo (callback) {
    // Do a lot of complex things

    callback();
}

// Those two have the same effect, but the later is more elegant
foo(function() {});
foo(angular.noop);

Solution 2:

I find it extremely helpful when writing a function that expects a callback.

Example:

function myFunction(id, value, callback) {

    // some logic
    return callback(someData);
}

The function above will return an error, when it gets called without specifying the third argument. myFunction(1, 'a');

Example (using angular.noop):

function myFunction(id, value, callback) {

    var cb = callback || angular.noop; // if no `callback` provided, don't break :)
    // some logic
    return cb(someData);
}

Solution 3:

It is a function that performs no operations. This is useful in situation like this:

function foo(y) {
   var x= fn();
   (y|| angular.noop)(x);
 }

It is useful when writing code in the functional style